BACKGROUND: Although the need for stemmed components is well accepted to improve mechanical survival in revision total knee arthroplasty (TKA), the ideal fixation method and stem design remain controversial. METHODS: We performed a retrospective review of 223 patients who underwent revision TKA in whom stemmed components had not been used previously and with a mean follow-up of 61.6 months, including 108 components with fully cemented stems and 316 components with "hybrid" press-fit stems. RESULTS: Based on a time to event model, risk for mechanical failure was equivalent for both cemented and hybrid stems (relative risk, 0.991; P = .98). Young age was the single greatest risk factor for mechanical failure (P = .006). Although there was a trend toward increased failure with cemented stems in patients aged <65 years, there was no significant difference in risk after accounting for covariates (relative risk, 1.4; P = .50). Intramedullary canal fill, not stem length or diameter, was the strongest predictor of failure with hybrid stems, and risk was reduced by 41.2% for each additional 10% canal fill. CONCLUSION: In conclusion, both cemented and hybrid modular stems are viable options in revision TKA. Surgeons should attempt to maximize canal filling of hybrid stems to obtain a solid press-fit. In addition, further studies are needed to evaluate the long-term survival of cemented stem fixation in young patients.
BACKGROUND: Although the need for stemmed components is well accepted to improve mechanical survival in revision total knee arthroplasty (TKA), the ideal fixation method and stem design remain controversial. METHODS: We performed a retrospective review of 223 patients who underwent revision TKA in whom stemmed components had not been used previously and with a mean follow-up of 61.6 months, including 108 components with fully cemented stems and 316 components with "hybrid" press-fit stems. RESULTS: Based on a time to event model, risk for mechanical failure was equivalent for both cemented and hybrid stems (relative risk, 0.991; P = .98). Young age was the single greatest risk factor for mechanical failure (P = .006). Although there was a trend toward increased failure with cemented stems in patients aged <65 years, there was no significant difference in risk after accounting for covariates (relative risk, 1.4; P = .50). Intramedullary canal fill, not stem length or diameter, was the strongest predictor of failure with hybrid stems, and risk was reduced by 41.2% for each additional 10% canal fill. CONCLUSION: In conclusion, both cemented and hybrid modular stems are viable options in revision TKA. Surgeons should attempt to maximize canal filling of hybrid stems to obtain a solid press-fit. In addition, further studies are needed to evaluate the long-term survival of cemented stem fixation in young patients.
Authors: Frank S Fröschen; Nadine Gravius; Jan-Frederic Lau; Thomas Martin Randau; Eva Kaup; Max J Friedrich; Sascha Gravius Journal: Int Orthop Date: 2018-12-11 Impact factor: 3.075
Authors: Bernard P Kemker; Christopher B Sowers; Raees Seedat; Jibanananda Satpathy; Nirav K Patel; Daniel J Lombardo; Gregory J Golladay Journal: Front Surg Date: 2022-03-11